ML20214M426
| ML20214M426 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 05/27/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20214M413 | List: |
| References | |
| NUDOCS 8706010303 | |
| Download: ML20214M426 (2) | |
Text
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NUCLEAR REGULATORY COMMISSION g(;fj i
WASHINGTON D.C.20555 E
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.109 TO FACILITY OPERATING LICENSE NO. DPR-71 AND AMENDMENT NO.136 TO FACILITY OPERATING LICENSE NO. DPR-62 I
CAROLINA POWER & LIGHT COMPANY i
BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 DOCKETS NOS. 50-325 AND 50-324
1.0 INTRODUCTION
The Carolina Power & Light Company, by "05000324/LER-1986-023-01, :on 861009,primary Containment Group 4 Isolation of HPCI Sys Occurred.Caused by Loss of Electrical Continuity at Terminal Connections of Thermocouple Leads. Thermocouple [[Atomic Element" contains a listed "[" character as part of the property label and has therefore been classified as invalid. Terminations Improved|letter dated November 7, 1986]], proposed changes to the Technical Specifications regarding loads on the B division battery bus. The proposed changes revise Surveillance Requirements 4.8.2.3.1.(b) by deleting specific reference to 37.5 kVA power conversion modules and adding a definition of acceptable load configurations for the B division battery bus.
2.0 EVALUATION The B division battery bus of each of the Brunswick Units is configured such that it is the nonnal supply to a unit's lighting inverter and standby Uninterruptible Power Supply (UPS).
In addition, the B division bus serves as the alternate supply for the opposite unit's lighting inverter. Each of the lighting inverters and the power conversion module for the UPS is currently rated at 37.5 kVA.
In 1984, the licensee completed a detailed DC battery load study. This study evaluated the sequential loading of the batteries during the worst case design basis event. The design basis event assumed for the study was a complete loss of offsite power coincident with a large and/or small break loss of coolant accident on one unit and a safe shutdown of the other unit.
One assumption of the load study was that no more than two of the possible three 37.5 kVA power conversion modules will be aligned to the B division bus at any time. The largest load on the battery for the load study occurs when two lighting inverters are aligned to the B division bus.
In an effort to ensure that no more than two of the 37.5 kVA power conversion modules are aligned to the B division bus at any time, the licensee incorporated the result of the load study into Surveillance Requirement 4.8.2.3.1.(b) of the Brunswick Technical Specifications. This surveillance requirement currently l
requires verification at least once per seven days that there are no more than two 37.5 kVA power conversion modules aligned to the B division bus.
In addition, the licensee has an operating procedure to ensure that not more than two of the three modules are connected to the DC bus at any time.
i The UPS system is a non-1E system which feeds various non-essential loads j
throughout the plant. The licensee intends to replace the obsolete exist-I ing 37.5 kVA UPS system, which includes a primary power converter unit, a s706010303 870527
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. 5 standby power converter unit, and switching modules with new equipment rated at 50 kVA. The UPS system modification is scheduled to be completed for Unit I during the current refueling outage.
The proposed modification of the UPS system (50 kVA) was evaluated for its impact on the DC battery load study. The loads fed from the UPS power con-version module are not altered by this modification. However, there is an increase in the load from the batteries due to a decrease in the efficiency of the new 50 kVA system. Even with the additional 20 amp increase, the configuration of two lighting inverters is a conservative loading of the B division battery and bus. The loading of the power conversion modules does not exceed the combination of the greatest. load on the battery system which was used for the load study. While the capacity margin of the batteries is slightly reduced, the proposed modification has been bounded by the 1984 battery load study. The proposed change to Surveillance Requirement 4.8.2.3.1.(b) to delete reference to 37.5 kVA power conversion modules and to clearly add a definition of the load configuration is ac-ceptable.
3.0 ENVIRONMENTAL CONSIDERATION
S An Environmental Assessment has been prepared pursuant to 10 CFR Part 51.32 and published in the FEDERAL REGISTER on l
4.0 CONCLUSION
The Commission has issued a " Notice of Consideration of Issuance of Amend-ments to Facility Operating Licenses and Opportunity for Prior Hearing" which was published in the FEDERAL REGISTER (51 FR 44158) on December 8, 1986, and consulted with the State of North Carolina. No public coments or requests for hearing were received, and the State of North Carolina did i
not have any comments.
We have concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Com-mission's regulations, and the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
S. Rhow 4
Dated:
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